This mostly black wizard hat with white lines going upward is a swirl is a normal hat at first glance, but taking a closer look reveals what the hat capable of.

Looking at this hat for 6 seconds (1 action) directly, or having this hat for 12 seconds in your peripheral vision makes you dizzy as the pattern on the hat begins to twist and turn. 

Must make a wisdom saving throw: DC (8 + proficiency bonus + INT modifier) Failing this saving throw causes the target to become dizzy and have disadvantage on attack rolls on their next turn and have half their movement as their vision is spun into a swirl. 

The creature wearing this hat also has a +5 to deception checks and a +3 to Intelligence.

Notes: Bonus: Deception, Bonus: Intelligence Score